Tutorial by Examples: w

Hello World

Content has been moved back to the good 'ol JSF wiki page

jsf • Getting started with jsf

Create a new file named hello_world.dart with the following content: void main() { print('Hello, World!'); } In the terminal, navigate to the directory containing the file hello_world.dart and type the following: dart hello_world.dart Hit enter to display Hello, World! in the terminal wi...

dart • Getting started with dart

Reading a whole file at once

File f = new File(path); String content = new Scanner(f).useDelimiter("\\Z").next(); \Z is the EOF (End of File) Symbol. When set as delimiter the Scanner will read the fill until the EOF Flag is reached.

Java Language • File I/O

Hello World application

To create and run new WPF project in Visual Studio: Click File → New → Project Select template by clicking Templates → Visual C# → Windows → WPF Application and press OK: Open MainWindow.xaml file in Solution Explorer (if you don't see Solution Explorer window, open it by clicking V...

wpf • Getting started with wpf

Hello World!

We start with creating an HTML page for the app. There we define the meta tags, a script tag to load the SAPUI5 libraries, and a placeholder for the content of the app. <!DOCTYPE html> <html> <head> <meta http-equiv="X-UA-Compatible" content="IE=edge"...

sapui5 • Getting started with sapui5

Show 'Hello World' using the VCL

This progam uses VCL, the default UI components library of Delphi, to print "Hello World" into a message box. The VCL wrapps most of the commonly used WinAPI components. This way, they can be used much easier, e.g. without the need to work with Window Handles. To include a dependency (lik...

Embarcadero Delphi • Getting started with Embarcadero Delphi

Hello World

Create hello.py: from flask import Flask app = Flask(__name__) @app.route('/') def hello(): return 'Hello, World!' Then run it with: export FLASK_APP=hello.py flask run * Running on http://localhost:5000/ Adding the code below will allow running it directly with python hello...

Flask • Getting started with Flask

Do not name a variable with an existing function name

There is already a function sum(). As a result, if we name a variable with the same name sum = 1+3; and if we try to use the function while the variable still exists in the workspace A = rand(2); sum(A,1) we will get the cryptic error: Subscript indices must either be real positive integer...

MATLAB Language • Common mistakes and errors

Creating a new project in Visual Studio (console application) and Running it in Debug mode

Download and install Visual Studio. Visual Studio can be downloaded from VisualStudio.com. The Community edition is suggested, first because it is free, and second because it involves all the general features and can be extended further. Open Visual Studio. Welcome. Go to File → New ...

C# Language • Getting started with C# Language

What causes Backtracking?

To find a match, the regex engine will consume characters one by one. When a partial match begins, the engine will remember the start position so it can go back in case the following characters don't complete the match. If the match is complete, the is no backtracking If the match isn't complete...

Regular Expressions • Backtracking

Why can backtracking be a trap?

Backtracking can be caused by optional quantifiers or alternation constructs, because the regex engine will try to explore every path. If you run the regex a+b against aaaaaaaaaaaaaa there is no match and the engine will find it pretty fast. But if you change the regex to (aa*)+b the number of comb...

Regular Expressions • Backtracking

Test flags-style enum values with bitwise logic

A flags-style enum value needs to be tested with bitwise logic because it may not match any single value. [Flags] enum FlagsEnum { Option1 = 1, Option2 = 2, Option3 = 4, Option2And3 = Option2 | Option3; Default = Option1 | Option3, } The Default value is actually a ...

C# Language • Enum

Animate a view from one position to another.

Objective-C CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position.x"]; animation.fromValue = @0; animation.toValue = @320; animation.duration = 1; [_label.layer addAnimation:animation forKey:@"basic"]; Swift let animation = CAB...

iOS • CAAnimation

Animate View - Toss

OBJECTIVE-C CATransition* transition = [CATransition animation]; transition.startProgress = 0; transition.endProgress = 1.0; transition.type = @"flip"; transition.subtype = @"fromLeft"; transition.duration = 0.8; transition.repeatCount = 5; [_label.layer addAnimation:tran...

iOS • CAAnimation

Revolve View

CGRect boundingRect = CGRectMake(-150, -150, 300, 300); CAKeyframeAnimation *orbit = [CAKeyframeAnimation animation]; orbit.keyPath = @"position"; orbit.path = CFAutorelease(CGPathCreateWithEllipseInRect(boundingRect, NULL)); orbit.duration = 4; orbit.additive = YES; orbit.repeatC...

iOS • CAAnimation

Shake View

Objective-C CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"position.x"]; animation.values = @[ @0, @10, @-10, @10, @0 ]; animation.keyTimes = @[ @0, @(1 / 6.0), @(3 / 6.0), @(5 / 6.0), @1 ]; animation.duration = 0.4; animation.additive = YES; [_label.lay...

iOS • CAAnimation

Dumping with Style

Sometimes Data::Dumper is not enough. Got a Moose object you want to inspect? Huge numbers of the same structure? Want stuff sorted? Colored? Data::Printer is your friend. use Data::Printer; p $data_structure; Data::Printer writes to STDERR, like warn. That makes it easier to find the outpu...

Perl Language • Debug Output

A complete hello world example.

Step 1 If you already have Django installed, you can skip this step. pip install Django Step 2 Create a new project django-admin startproject hello That will create a folder named hello which will contain the following files: hello/ ├── hello/ │ ├── __init__.py │ ├── settings.py │...

Django • Getting started with Django

"do ... while" loop

var availableName; do { availableName = getRandomName(); } while (isNameUsed(name)); A do while loop is guaranteed to run at least once as it's condition is only checked at the end of an iteration. A traditional while loop may run zero or more times as its condition is checked at the begin...

JavaScript • Loops

Well-formedness

An XML document is a text file that conforms to the XML specification's well-formedness rules. Such a conforming document is said to be well-formed (not to be confused with valid). XML is very strict with well-formedness in comparison to other languages such as HTML. A text file that is not well-for...

xml • Getting started with xml